drag and drop

src/card/drag.rs

@@ -1,4 +1,68 @@
 use bevy::prelude::*;
 
+use crate::{animation::transform::AnimatedTransform, card::Hand};
+
 #[derive(Component)]
 pub struct DraggableCard;
+
+#[derive(Component)]
+pub struct DraggedCard;
+
+#[derive(Resource)]
+pub struct MousePosition(pub Vec3);
+
+pub fn mouse_position_system(
+    mut mouse: ResMut<MousePosition>,
+    window: Single<&Window>,
+    camera: Single<(&Camera, &GlobalTransform)>,
+) {
+    if let Some(Ok(mouse_pos)) = window
+        .cursor_position()
+        .and_then(|viewport_pos| Some(camera.0.viewport_to_world_2d(camera.1, viewport_pos)))
+    {
+        mouse.0 = Vec3 {
+            x: mouse_pos.x,
+            y: mouse_pos.y,
+            z: 0.,
+        }
+    }
+}
+
+pub fn card_drag_start(
+    event: On<Pointer<DragStart>>,
+    mut commands: Commands,
+    card_query: Query<(), With<DraggableCard>>,
+    dragged_option: Option<Single<&DraggedCard>>,
+) {
+    if dragged_option.is_some() {
+        return;
+    }
+    if let Err(_) = card_query.get(event.entity) {
+        return;
+    }
+
+    commands
+        .entity(event.entity)
+        .insert(DraggedCard)
+        .remove_parent_in_place();
+}
+
+pub fn card_drag(
+    _: On<Pointer<Drag>>,
+    mut card_transform: Single<&mut AnimatedTransform, With<DraggedCard>>,
+    mouse_pos: Res<MousePosition>,
+) {
+    card_transform.translation = mouse_pos.0;
+}
+
+pub fn card_drag_end(
+    _: On<Pointer<DragEnd>>,
+    mut commands: Commands,
+    dragged: Single<Entity, With<DraggedCard>>,
+    hand: Single<Entity, With<Hand>>,
+) {
+    commands
+        .entity(dragged.entity())
+        .remove::<DraggedCard>()
+        .set_parent_in_place(hand.entity());
+}